Novel Carbazol-Pyridine-Carbonitrile Derivative as Excellent Blue Thermally Activated Delayed Fluorescence Emitter for Highly Efficient Organic Light-Emitting Devices

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• 作者：Wei Liu ; Cai-Jun Zheng ; Kai Wang ; Zhan Chen ; Dong-Yang Chen ; Fan Li ; Xue-Mei Ou ; Yu-Ping Dong ; Xiao-Hong Zhang
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2015
• 出版时间：September 2, 2015
• 年：2015
• 卷：7
• 期：34
• 页码：18930-18936
• 全文大小：393K
• ISSN：1944-8252

文摘

A novel blue thermally activated delayed fluorescence (TADF) emitter, CPC (2,6-di(9H-carbazol-9-yl)-4-phenylpyridine-3,5-dicarbonitrile), was designed and synthesized. By directly linking carbazole (to serve as electron-donor) and pyridine-3,5-dicarbonitrile (to serve as electron-acceptor), and distributing cyanogroups and carbazole groups at the para-position of pyridine core, CPC successfully achieves an extremely small singlet鈥搕riplet splitting and fairish photoluminescence quantum yield, thus can act as the highly efficient blue TADF emitter. The optimized organic light-emitting diode (OLED) based on 13 wt % CPC doped in mCP (1,3-bis(9H-carbazol-9-yl)benzene) host exhibits maximum current efficiency, power efficiency, and external quantum efficiency of 47.7 cd A^鈥?, 42.8 lm W^鈥?, and 21.2%, respectively, which are the best results in reported blue TADF-based devices up to date and even comparable with the best reported blue phosphorescent OLEDs.